Multi-Source Data-Driven Structural Equation Modeling Analysis of Intercity Travel Behavior under the Toll-Free Highway Policy during Holidays

During public holidays in China, intercity travel surges sharply, causing widespread highway congestion. This study investigates the mechanisms behind holiday-related congestion, with a focus on the toll-free highway policy implemented during national holidays. Using data from the Yangtze River Delta, this study combined Baidu migration data, time-series analysis, and structural equation modeling to examine the direct and indirect effects of toll-free highway policy, transport accessibility, urban spatial structure, and socioeconomic factors on travel behavior. Results showed that the toll-free policy had the strongest direct effect on travel intensity, followed by urban spatial structure, while transport accessibility played a relatively limited role. Socioeconomic attributes had the most pronounced indirect effect through their effects on urban spatial structure. Based on these findings, we recommend targeted strategies such as time-based adjustment, distance-based graduated tolling, and city-specific tolling schemes. This study provides empirical evidence and policy implications for optimizing highway management during national holidays.